In microscopes and other optical instruments there is often a need to provide different factors of magnification depending on what type of object is being imaged and the desired level of details. This is conventionally achieved by an objective lens changer carrying two or more lenses of different magnification that can be selectively positioned in the optical path of the optical instrument. FIG. 1 shows a prior-art objective lens changer 10 comprising an objective turret 20 with three objective lens positions 30, and wherein the turret is rotated about its center to change objective lens in the optical path. FIG. 2 shows an alternative objective lens changer 40 of pivotal type comprising two objective lens positions 30.